In this paper we focus on a laser/dry etch mask process simulation. Using Mentor Graphics Calibre RET tool suite, we exploit the similarity between the image on laser based mask writers and the image on wafer steppers. Doing so, we adapt a 'Silicon process simulation' to a 'mask process simulation'. The mask process tuning is performed with Mentor test patterns and then we simulate the mask image of a 4x scale database. The result is saved as a 1x scale gds file and is used, in a normal way, for a 193nm lithography simulation. We notice a large difference between the aerial image of the 193nm lithography based on the database and the one based on the mask process simulation.